Premises-based WAN optimization usually needs an appliance, be it a physical box or a virtual partition with its own dedicated hardware resources. Certeon on Tuesday announced plans to change this through aCelera Enterprise for Windows, a version of its aCelera WAN optimization that can run on a Windows Server 2008 R2 alongside any other application. The intent is to make WAN optimization more widely applicable in locations that can't justify dedicated hardware or even server virtualization.

"It's comparable to a line-of-business application," said Donato Buccella, Certeon's chief technology officer, in an interview. "It can share the server with other applications without affecting performance." To avoid hindering other Windows applications, IT can set limits on the aCelera's resource use. Performance of course depends on these limits, but Certeon claims that it is comparable to the virtual appliances and even hardware used by other vendors, supporting 6,000 concurrent connections on a machine with 2 CPUs and 8 GB of RAM.

"We're aiming for smaller offices that don't have virtualization, or medium to large offices that have hardware limitations," said Buccella. These limitations most often apply to locations without dedicated IT personnel, to which servers are shipped out preconfigured and without the possibility of upgrades. Certeon said that it's seeing particular interest from franchisees, whose server configuration is often restricted by the franchise owner on whom they rely for technical support. In most cases, the Windows-based software optimizes links that have a traditional aCelera virtual appliance at the other end, which can be either in an enterprise data center or part of a hosted cloud service.

Certeon abandoned physical boxes in favor of virtual appliances more than two years ago, so a move into software at the application level isn't unexpected. However, many users may be skeptical that a program running under Windows can match the performance of a dedicated virtual appliance. "What we say is, do a test," said Buccella. "We're solving problems of latency, mitigated mostly at Layer 7." According to Certeon, this Layer 7 functionality helps it achieve higher performance than competitors that use similar hardware but aim for the TCP or even IP level. The downside of Layer 7 is that it entails a narrows focus on just a few application protocols such as HTTP and those used by SharePoint and Exchange, so customers need to check carefully that their applications are supported.

Server software isn't the only way to roll out WAN optimization to branch offices that can't support appliances. Service providers including Aryaka and Ipanema offer similar functionality without any client-side software, a feature that Akamai may match through its partnership with Riverbed. "Certeon doesn't see these as a threat, as they can't fully optimize the links between carrier points of presence and the enterprise. "You get the best optimization by putting accelerators closer to applications," said Buccella. This is true in most cases, though putting accelerators close to applications also increases the need for IT support and installation work. A software accelerator may help, but customers will still need to consider the tradeoff between complexity and performance.

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